Remove VirtualExecutorUtil.java (#7263)

common/configurable/src/main/java/io/helidon/common/configurable/ObserverManager.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022 Oracle and/or its affiliates.
+ * Copyright (c) 2022, 2023 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package io.helidon.common.configurable;
 
 import java.lang.System.Logger.Level;
@@ -22,6 +23,7 @@
 import java.util.ServiceLoader;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
@@ -216,7 +218,7 @@ private static class MethodInvocationImpl implements ExecutorServiceSupplierObse
         private final Class<?> type;
 
         private static final LazyValue<ExecutorService> VIRTUAL_EXECUTOR_SERVICE = LazyValue
-                .create(VirtualExecutorUtil::executorService);
+                .create(Executors::newVirtualThreadPerTaskExecutor);
 
         static MethodInvocationImpl create(String displayName, String description, String methodName)  {
             ExecutorService executorService = VIRTUAL_EXECUTOR_SERVICE.get();

common/configurable/src/main/java/io/helidon/common/configurable/ThreadPoolSupplier.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2022 Oracle and/or its affiliates.
+ * Copyright (c) 2018, 2023 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,8 @@
 package io.helidon.common.configurable;
 
 import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -72,7 +74,7 @@ private ThreadPoolSupplier(Builder builder) {
         this.growthThreshold = builder.growthThreshold;
         this.growthRate = builder.growthRate;
         this.rejectionHandler = builder.rejectionHandler == null ? DEFAULT_REJECTION_POLICY : builder.rejectionHandler;
-        this.useVirtualThreads = builder.useVirtualThreads || builder.virtualThreadsEnforced;
+        this.useVirtualThreads = builder.useVirtualThreads;
         ObserverManager.registerSupplier(this, name, "general", useVirtualThreads);
     }
 
@@ -111,10 +113,8 @@ public static ThreadPoolSupplier create(String name) {
 
     ExecutorService getThreadPool() {
         if (useVirtualThreads) {
-            if (VirtualExecutorUtil.isVirtualSupported()) {
-                LOGGER.log(System.Logger.Level.TRACE, "Using unbounded virtual executor service for pool " + name);
-                return ObserverManager.registerExecutorService(this, VirtualExecutorUtil.executorService());
-            }
+            ThreadFactory factory = Thread.ofVirtual().name(name + "-", 0).factory();
+            return ObserverManager.registerExecutorService(this, Executors.newThreadPerTaskExecutor(factory));
         }
 
         ThreadPool result = ThreadPool.create(name,
@@ -165,7 +165,6 @@ public static final class Builder implements io.helidon.common.Builder<Builder,
         private ThreadPool.RejectionHandler rejectionHandler = DEFAULT_REJECTION_POLICY;
         private String name;
         private boolean useVirtualThreads;
-        private boolean virtualThreadsEnforced;
 
         private Builder() {
         }
@@ -186,13 +185,6 @@ public ThreadPoolSupplier build() {
                 rejectionHandler = DEFAULT_REJECTION_POLICY;
             }
 
-            if (virtualThreadsEnforced) {
-                if (!VirtualExecutorUtil.isVirtualSupported()) {
-                    throw new IllegalStateException("Virtual threads are required, yet not available on this JVM. "
-                                                            + "Please use a Loom build.");
-                }
-            }
-
             return new ThreadPoolSupplier(this);
         }